allow adding erased msgs

lib/msg-v3/validation.js

@@ -298,18 +298,21 @@ function validateData(msg) {
  * @param {Msg} msg
  */
 function validateDataSizeHash(msg) {
-  const [dataHash, dataSize] = representData(msg.data)
-  if (!Number.isSafeInteger(dataSize) || dataSize < 0) {
+  const { dataHash: actualHash, dataSize: actualSize } = msg.metadata
+  if (!Number.isSafeInteger(actualSize) || actualSize < 0) {
     // prettier-ignore
-    return `invalid msg: dataSize ${dataSize} should have been an unsigned integer\n` + JSON.stringify(msg)
+    return `invalid msg: dataSize ${actualSize} should have been an unsigned integer\n` + JSON.stringify(msg)
   }
-  if (dataHash !== msg.metadata.dataHash) {
+
+  if (msg.data === null) return
+  const [expectedHash, expectedSize] = representData(msg.data)
+  if (actualHash !== expectedHash) {
     // prettier-ignore
-    return `invalid msg: data hash "${dataHash}" does not match metadata.dataHash "${msg.metadata.dataHash}"\n` + JSON.stringify(msg)
+    return `invalid msg: metadata.dataHash "${actualHash}" should have been "${expectedHash}"\n` + JSON.stringify(msg)
   }
-  if (dataSize !== msg.metadata.dataSize) {
+  if (expectedSize !== msg.metadata.dataSize) {
     // prettier-ignore
-    return `invalid msg: data size "${dataSize}" does not match metadata.dataSize "${msg.metadata.dataSize}"\n` + JSON.stringify(msg)
+    return `invalid msg: metadata.dataSize ${actualSize} should have been "${expectedSize}"\n` + JSON.stringify(msg)
   }
 }
 

test/msg-v3/validate.test.js

@@ -136,3 +136,32 @@ test('validate 2nd forked msg', (t) => {
   const err = MsgV3.validate(msg1B, tangle, pubkeys, msgID1B, mootID)
   assert.ifError(err, 'valid 2nd forked msg')
 })
+
+test('validate erased msg', (t) => {
+  const keypair = Keypair.generate('ed25519', 'alice')
+  const account = MsgV3.getMsgID(
+    MsgV3.createAccount(keypair, 'person', 'alice')
+  )
+  const pubkeys = new Set([keypair.public])
+
+  const moot = MsgV3.createMoot(account, 'post', keypair)
+  const mootID = MsgV3.getMsgID(moot)
+  const tangle = new MsgV3.Tangle(mootID)
+  tangle.add(mootID, moot)
+
+  const msg1 = MsgV3.create({
+    account,
+    accountTips: [account],
+    domain: 'post',
+    data: { text: 'Hello world!' },
+    tangles: {
+      [mootID]: tangle,
+    },
+    keypair,
+  })
+  msg1.data = null
+  const msgID1 = MsgV3.getMsgID(msg1)
+
+  const err = MsgV3.validate(msg1, tangle, pubkeys, msgID1, mootID)
+  assert.ifError(err, 'valid erased msg')
+})